Azathioprine and 6-mercaptopurine for maintenance of surgically-induced remission in Crohn's disease

Maintaining remission in Crohn's disease post surgery: what can we learn from Cochrane?

Surgery is a vital pillar in the management of Crohn's disease and medical options for prevention of recurrence after surgery are a key consideration. The main classes of effective induction therapies have very different efficacy data for maintenance and this is more pronounced in the postsurgical setting. In this review article, the up-to-date Cochrane reviews on the topic are presented, including a network meta-analysis. The Cochrane evidence shows a high relapse rate in the first 5 years after surgery with placebo or no treatment. The reviews demonstrate that 5-aminosalicylic acid (5-ASA) agents are probably more effective than placebo on pairwise and network meta-analysis, with moderate certainty evidence of a number needed to treat (NNT) of 13. The Cochrane evidence demonstrates that adalimumab may be more effective than placebo on pairwise and network meta-analysis, with low certainty evidence of an NNT of 2. Thiopurine analogues may be effective on pairwise analysis, but may not be effective on network meta-analysis. There was no evidence to support the use of any other agent but these findings are of low and very low certainty. It is proposed that clinicians should consider adalimumab, 5-ASA and thiopurine analogue agents based on the findings of the Cochrane synthesis. The use of the evidence, including the Grading of Recomendations, Assessment, Development, and Evaluations (GRADE) certainty and magnitude of effect data, can support discussions with patients. Future research is needed to consider other therapies that are effective in medically induced maintenance given the low certainty of evidence limiting conclusions, either supporting or refuting their use.

Infliximab for maintenance of medically-induced remission in Crohn's disease

BACKGROUND

Infliximab is a monoclonal antibody that binds and neutralises tumour necrosis factor-alpha (TNF-α) which is present in high levels in the blood serum, mucosa and stool of patients with Crohn's disease.

OBJECTIVES

To determine the efficacy and safety of infliximab for maintaining remission in patients with Crohn's disease.

SEARCH METHODS

On 31 August, 2021 and 23 June, 2023, we searched CENTRAL, Embase, MEDLINE, ClinicalTrials.gov, and WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which infliximab was compared to placebo or another active comparator for maintenance, remission, or response in patients with Crohn's disease.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies and conducted data extraction and risk of bias assessment. We expressed outcomes as risk ratios and mean differences with 95% confidence intervals. We assessed the certainty of the evidence using GRADE. Our primary outcome was clinical relapse. Secondary outcomes were loss of clinical response, endoscopic relapse, and withdrawal due to serious and adverse events.

MAIN RESULTS

Nine RCTs with 1257 participants were included. They were conducted between 1999 and 2022; seven RCTs included biologically-naive patients, and the remaining two included a mix of naive/not naive patients. Three studies included patients in clinical remission, five included patients with a mix of activity scores, and one study included biologic responders with active disease at baseline. All studies allowed some form of concomitant medication during their duration. One study exclusively included patients with fistulating disease. The age of the participants ranged from 18 to 69 years old. All but one single-centre RCT were multicentre RCTs. Four studies were funded by pharmaceutical companies, two had a mix of commercial and public funding, and two had public funding. Infliximab is probably superior to placebo in preventing clinical relapse in patients who have mixed levels of clinical disease activity at baseline, and are not naive to biologics (56% vs 75%, RR 0.73, 95% CI 0.63 to 0.84, NNTB = 5, moderate-certainty evidence). We cannot draw any conclusions on loss of clinical response (RR 0.59, 95% CI 0.37 to 0.96), withdrawals due to adverse events (RR 0.66, 95% CI 0.37 to 1.19), or serious adverse events (RR 0.60, 95% CI 0.36 to 1.00) because the evidence is very low certainty. Infliximab combined with purine analogues is probably superior to purine analogues for clinical relapse (12% vs 59%, RR 0.20, 95% CI 0.10 to 0.42, NNTB = 2, moderate-certainty evidence), for patients in remission, and who are not naive to biologics. We cannot draw any conclusions on withdrawals due to adverse events (RR 0.47, 95% CI 0.15 to 1.49), and serious adverse events (RR 1.19, 95% CI 0.54 to 2.64) because the evidence is very low certainty. We cannot draw any conclusions about the effects of infliximab on serious adverse events compared to purine analogues (RR 0.79, 95% CI 0.37 to 1.68) for a population in remission at baseline because the evidence is very low certainty. There was no evidence available for the outcomes of clinical relapse, loss of clinical response, and withdrawal due to adverse events. Infliximab may be equivalent to biosimilar for clinical relapse (47% vs 40% RR 1.18, 95% CI 0.82 to 1.69), and it may be slightly less effective in averting loss of clinical response (49% vs 32%, RR 1.50, 95% CI 1.01 to 2.23, low-certainty evidence), for a population with mixed/low disease activity at baseline. Infliximab may be less effective than biosimilar in averting withdrawals due to adverse events (27% vs 0%, RR 20.73, 95% CI 2.86 to 150.33, low-certainty evidence). Infliximab may be equivalent to biosimilar for serious adverse events (10% vs 10%, RR 0.99, 95% CI 0.39 to 2.50, low-certainty evidence). We cannot draw any conclusions on the effects of subcutaneous biosimilar compared with intravenous biosimilar on clinical relapse (RR 1.01, 95% CI 0.65 to 1.57), loss of clinical response (RR 0.94, 95% CI 0.70 to 1.25), and withdrawals due to adverse events (RR 0.77, 95% CI 0.30 to 1.97) for an active disease population with clinical response at baseline because the evidence is of very low certainty. We cannot draw any conclusions on the effects of infliximab compared to adalimumab on loss of clinical response (RR 0.68, 95% CI 0.29 to 1.59), withdrawals due to adverse events (RR 0.10, 95% CI 0.01 to 0.72), serious adverse events (RR 0.09, 95% CI 0.01 to 1.54) for an active disease population with clinical response at baseline because the evidence is of very low certainty. There was no evidence available for the outcome of clinical relapse.

AUTHORS' CONCLUSIONS

Infliximab is probably more effective in preventing clinical relapse than placebo (moderate-certainty evidence). Infliximab in combination with purine analogues is probably more effective in preventing clinical and endoscopic relapse than purine analogues alone (moderate-certainty evidence). No conclusions can be drawn regarding prevention of loss of clinical response, occurrence of withdrawals due to adverse events, or total adverse events due to very low-certainty evidence for both of these comparisons. There may be little or no difference in prevention of clinical relapse, withdrawal due to adverse events or total adverse events between infliximab and a biosimilar (low-certainty evidence). Infliximab may lead to more loss of clinical response than a biosimilar (low-certainty evidence). We were unable to draw meaningful conclusions about other comparisons and outcomes related to missing data or very low-certainty evidence due to serious concerns about imprecision and risk of bias. Further research should focus on comparisons with other active therapies for maintaining remission, as well as ensuring adequate power calculations and reporting of methods.

Uphill battle: Innovation of thiopurine therapy in global inflammatory bowel disease care

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract that encompasses two major conditions: Crohn's disease (CD) and ulcerative colitis (UC). Historically, IBD has been primarily reported in western countries, but over the past decades, its prevalence is rapidly increasing, especially in lower and middle-income countries (LMICs) such as India and China and also in Sub-Saharan Africa. The prevalence of IBD in LMICs has been the subject of growing concern due to the impact of access to public healthcare and the burden it places on healthcare resources. The classical thiopurines face significant challenges due to cessation of therapy in approximately half of patients within one year due to side effects or ineffectiveness. In this article, we highlight innovating thiopurine treatment for IBD patients in downregulating side effects and improving efficacy.

What Happens to Patients with Inflammatory Bowel Disease Who Are Intolerant to Thiopurines?

Introduction

The clinical consequences for patients with inflammatory bowel disease (IBD) who stop treatment owing to side effects have not been fully investigated.

Methods

This retrospective observational study aimed to compare patients who discontinued thiopurine treatment due to side effects with those who tolerated thiopurine treatment in the use of other IBD drugs, surgery, and fecal calprotectin values in the first 5 years after the start of thiopurine treatment.

Results

The proportion of patients with IBD who initiated thiopurine treatment at our clinic was 44% (32% ulcerative colitis and 64% Crohn's disease) and 31% (n = 94) of those patients had to stop thiopurine treatment within 5 years due to side effects. Patients who discontinued thiopurine treatment due to intolerance were significantly older (median age 33 vs. 27 years, p = 0.003), significantly more often used prednisolone (89 vs. 76%, p = 0.009), and used to a lesser extent TNF inhibitors at the start of thiopurine treatment (3% vs. 9%, p = 0.062). Budesonide treatment and non-TNF inhibitor second-line therapy were significantly more commonly used in patients who discontinued thiopurine treatment owing to side effects, but there were no statistically significant differences in the use of other treatments. The proportion of patients with a median FC >200 μg/g was significantly higher during follow-up in patients with UC who discontinued thiopurine treatment owing to side effects.

Conclusions

Patients who discontinued thiopurines owing to side effects were prescribed more budesonide and non-TNF inhibitor second-line therapy, but there were no differences in the use of TNF inhibitors, prednisolone, or surgery.

Infliximab for medical induction of remission in Crohn's disease

BACKGROUND

Infliximab is a monoclonal antibody that binds and neutralises tumour necrosis factor-alpha (TNF-α), which is present in high levels in the blood serum, mucosa and stool of people with Crohn's disease.

OBJECTIVES

To evaluate the benefits and harms of infliximab alone or in combination with another agent for induction of remission in Crohn's disease compared to placebo or active medical therapies.

SEARCH METHODS

On 31 August 2021 and 4 March 2023, we searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov and World Health Organization ICTRP.

SELECTION CRITERIA

Randomised control trials (RCTs) comparing infliximab alone or in combination with another agent to placebo or another active comparator in adults with active Crohn's disease.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies and conducted data extraction and risk of bias assessment. We expressed outcomes as risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI). We assessed the certainty of the evidence using GRADE. Our primary outcomes were clinical remission, clinical response and withdrawals due to adverse events. Our secondary outcomes were endoscopic remission, histological remission, endoscopic response, and serious and total adverse events.

MAIN RESULTS

The search identified 10 RCTs with 1101 participants. They were conducted between 1999 and 2019, and 7/10 RCTs included biologically naive participants. All but one RCT, which did not provide information, were multicentre and funded by pharmaceutical companies, and their authors declared conflicts. The age of the participants ranged from 26 to 65 years. Results were based on one study unless otherwise stated. Infliximab 5 mg/kg to 10 mg/kg may be more effective than placebo at week four for clinical remission (30/55 versus 3/25; RR 4.55, 95% CI 1.53 to 13.50; number needed to treat for an additional beneficial outcome (NNTB) 3) and response (36/55 versus 4/25; RR 4.09, 95% CI 1.63 to 10.25, NNTB 3). The evidence was low certainty. The study did not report withdrawals due to adverse events. We could not draw conclusions on the effects of infliximab 5 mg/kg to 10 mg/kg compared to placebo for fistulating participants for clinical remission (29/63 versus 4/31; RR 3.57, 95% CI 1.38 to 9.25; NNTB 4), response (48/106 versus 15/75; RR 1.94, 95% CI 1.10 to 3.41; NNTB 6; 2 studies) or withdrawals due to adverse events (2/63 versus 0/31; RR 2.50, 95% CI 0.12 to 50.54). The evidence was very low certainty. Infliximab used in combination with purine analogues is probably more effective than purine analogues alone for clinical remission at weeks 24 to 26 (182/301 versus 95/302; RR 1.92, 95% CI 1.59 to 2.32, NNTB 4; 4 studies; moderate-certainty evidence) and clinical response at week 26 (107/177 versus 66/178; RR 1.64, 95% CI 1.31 to 2.05; NNTB 5; 2 studies; moderate-certainty evidence). There may be little or no difference in withdrawals due to adverse events at week 26 (62/302 versus 53/301; RR 0.87, 95% CI 0.63 to 1.21; 4 studies; low-certainty evidence). Infliximab alone may be more effective than purine analogues alone at week 26 for clinical remission (85/177 versus 57/178; RR 1.50, 95% CI 1.15 to 1.95; NNTB 7; 2 studies) and response (94/177 versus 66/178; RR 1.44, 95% CI 1.13 to 1.82; NNTB 7; 2 studies). There may be little or no difference in withdrawals due to adverse events (30/177 versus 43/178; RR 0.70, 95% CI 0.46 to 1.06; 4 studies). The evidence was low certainty. We could not draw any conclusions on the effects of infliximab 5 mg/kg compared to 10 mg/kg for clinical remission (19/27 versus 11/28; RR 1.79, 95% CI 1.06 to 3.02) and response (22/27 versus 24/28; RR 1.63, 95% CI 1.08 to 2.46). The evidence was very low certainty. Withdrawals due to adverse events were not reported. We could not draw any conclusions on the effects of infliximab 5 mg/kg compared to 10 mg/kg in an exclusively fistulating population for clinical remission (17/31 versus 12/32; RR 1.46, 95% CI 0.84 to 2.53), response (21/31 versus 18/32; RR 1.20, 95% CI 0.82 to 1.78), or withdrawals due to adverse events (1/31 versus 1/32; RR 1.03, 95% CI 0.07 to 15.79). The evidence was very low certainty. We could not draw any conclusions on the effects of infliximab 5 mg/kg compared to 20 mg/kg for clinical remission (19/27 versus 11/28; RR 1.79, 95% CI 1.06 to 3.02) or response (22/27 versus 18/28; RR 1.27, 95% CI 0.91 to 1.76). The evidence was very low certainty. Withdrawals due to adverse events were not reported. We could not draw any conclusions on the effects of infliximab 10 mg/kg compared to 20 mg/kg for clinical remission (11/28 versus 11/28; RR 1.00, 95% CI 0.52 to 1.92) or response (14/28 versus 18/28; RR 0.78, 95% CI 0.49 to 1.23). The evidence was very low certainty. Withdrawals due to adverse events were not reported. There may be little or no difference between infliximab and a CT-P13 biosimilar at week six for clinical remission (47/109 versus 49/111; RR 0.98, 95% CI 0.72 to 1.32), response (67/109 versus 70/111; RR 0.97, 95% CI 0.79 to 1.20) and withdrawals due to adverse events (21/109 versus 17/111; RR 1.26, 95% CI 0.70 to 2.25). The evidence was low certainty.

AUTHORS' CONCLUSIONS

Infliximab in combination with purine analogues is probably more effective than purine analogues alone in inducing clinical remission and clinical response. Infliximab alone may be more effective in inducing clinical remission and response than purine analogues alone or placebo. Infliximab may be similar in efficacy to a CT-P13 biosimilar and there may be little or no difference in withdrawals due to adverse events. We were unable to draw meaningful conclusions as to whether infliximab alone is effective when used for exclusively fistulating populations. There was evidence that there may be little or no difference in withdrawal due to adverse events between infliximab plus purines compared with purines alone, as well as infliximab alone compared with purines alone. Meaningful conclusions cannot be drawn on all other outcomes related to adverse events due to very low certainty evidence.

Vitamin D for the treatment of inflammatory bowel disease

BACKGROUND

Vitamin D possesses immunomodulatory properties and has been implicated in the pathogenesis and severity of inflammatory bowel disease (IBD). Animal studies and emerging epidemiological evidence have demonstrated an association between vitamin D deficiency and worse disease activity. However, the role of vitamin D for the treatment of IBD is unclear.

OBJECTIVES

To evaluate the benefits and harms of vitamin D supplementation as a treatment for IBD.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was Jun 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in people of all ages with active or inactive IBD comparing any dose of vitamin D with another dose of vitamin D, another intervention, placebo, or no intervention. We defined doses as: vitamin D (all doses), any-treatment-dose vitamin D (greater than 400 IU/day), high-treatment-dose vitamin D (greater than 1000 IU/day), low-treatment-dose vitamin D (400 IU/day to 1000 IU/day), and supplemental-dose vitamin D (less than 400 IU/day).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. clinical response for people with active disease, 2. clinical relapse for people in remission, 3. quality of life, and 4. withdrawals due to adverse events. Our secondary outcomes were 5. disease activity at end of study, 6. normalisation of vitamin D levels at end of study, and 7. total serious adverse events. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included 22 RCTs with 1874 participants. Study duration ranged from four to 52 weeks. Ten studies enroled people with Crohn's disease (CD), five enroled people with ulcerative colitis (UC), and seven enroled people with CD and people with UC. Seventeen studies included adults, three included children, and two included both. Four studies enroled people with active disease, six enroled people in remission, and 12 enroled both. We assessed each study for risk of bias across seven individual domains. Five studies were at low risk of bias across all seven domains. Ten studies were at unclear risk of bias in at least one domain but with no areas of high risk of bias. Seven studies were at high risk of bias for blinding of participants and assessors. Vitamin D (all doses) versus placebo or no treatment Thirteen studies compared vitamin D against placebo or no treatment. We could not draw any conclusions on clinical response for UC as the certainty of the evidence was very low (risk ratio (RR) 4.00, 95% confidence interval (CI) 1.51 to 10.57; 1 study, 60 participants). There were no data on CD. There may be fewer clinical relapses for IBD when using vitamin D compared to placebo or no treatment (RR 0.57, 95% CI 0.34 to 0.96; 3 studies, 310 participants). The certainty of the evidence was low. We could not draw any conclusions on quality of life for IBD (standardised mean difference (SMD) -0.13, 95% CI -3.10 to 2.83 (the SMD value indicates a negligent decrease in quality of life, and the corresponding CIs indicate that the effect can range from a large decrease to a large increase in quality of life); 2 studies, 243 participants) or withdrawals due to adverse events for IBD (RR 1.97, 95% CI 0.18 to 21.27; 12 studies, 1251 participants; note 11 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 12). The certainty of the evidence was very low. High-treatment-dose vitamin D versus low-treatment-dose vitamin D Five studies compared high treatment vitamin D doses against low treatment vitamin D doses. There were no data on clinical response. There may be no difference in clinical relapse for CD (RR 0.48, 95% CI 0.23 to 1.01; 1 study, 34 participants). The certainty of the evidence was low. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 0.89, 95% CI 0.06 to 13.08; 3 studies, 104 participants; note 2 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 3). The data on quality of life and disease activity could not be meta-analysed, were of very low certainty, and no conclusions could be drawn. Any-treatment-dose vitamin D versus supplemental-dose vitamin D Four studies compared treatment doses of vitamin D against supplemental doses. There were no data on clinical response and relapse. There were no data on quality of life that could be meta-analysed. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 3.09, 95% CI 0.13 to 73.17; 4 studies, 233 participants; note 3 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 4).

AUTHORS' CONCLUSIONS

There may be fewer clinical relapses when comparing vitamin D with placebo, but we cannot draw any conclusions on differences in clinical response, quality of life, or withdrawals, due to very low-certainty evidence. When comparing high and low doses of vitamin D, there were no data for clinical response, but there may be no difference in relapse for CD. We cannot draw conclusions on the other outcomes due to very low certainty evidence. Finally, comparing vitamin D (all doses) to supplemental-dose vitamin D, there were no data on clinical relapse or response, and we could not draw conclusions on other outcomes due to very low certainty evidence or missing data. It is difficult to make any clear recommendations for future research on the basis of the findings of this review. Future studies must be clear on the baseline populations, the purpose of vitamin D treatment, and, therefore, study an appropriate dosing strategy. Stakeholders in the field may wish to reach consensus on such issues prior to new studies.

Prioritization in inflammatory bowel disease therapy

INTRODUCTION

Most guidelines for IBD still recommend step-by-step therapy with initially classic drugs such aminosalicylates (in ulcerative colitis) or steroids but avoid prioritizing certain biological drugs and JAK inhibitors in the complicated course. This review provides an aid to pending therapy decisions.

AREAS COVERED

In this review, we analyze the evidence for Crohn's disease as well as ulcerative colitis in order to optimize and 'personalize' the choice of therapy, especially in difficult cases. The relevant publications in Pubmed were identified in a continuous literature review with the key words 'Crohn´s disease' and 'ulcerative colitis.'

EXPERT OPINION

Based on this complex data set following standard therapies steroid-refractory Crohn´s disease should preferentially be treated with combined infliximab plus azathioprine or risankizumab, in second line after their failure with ustekinumab or 7adalimumab. In steroid-refractory ulcerative colitis infliximab plus azathioprine or upadacitinib should be preferred in first line, filgotinib, tofacitinib or ustekinumab in second line. A steroid-dependent course in both diseases requires azathioprine or vedolizumab, in second line infliximab or Janus kinase inhibitors. The conclusions drawn from these complex data may be helpful for individual decision making in daily clinical practice.

What's New in the Postoperative Management of Crohn's Disease?

Patients with Crohn's disease (CD) often require surgical resection due to complications, such as strictures and abscesses, or disease refractory to medical therapy. To understand the evolving management of patients with CD after surgery, we outline the risk factors for postoperative recurrence, advances in postoperative endoscopic evaluation and characterization of recurrence, noninvasive methods of assessing postoperative recurrence, use of postoperative prophylactic medical therapy including newer biologics, and novel surgical methods to reduce postoperative recurrence. The Rutgeerts score (RS) was developed to predict progression of disease based on endoscopic appearance postoperatively and to guide medical therapy. However, this scoring system groups ileal and anastomotic lesions into the same category. A modified RS was developed to separate lesions isolated to the anastomosis and those in the neo-terminal ileum to further understand the role of anastomotic lesions in CD progression. Additional scoring systems have also been evaluated to better understand these differences. In addition, noninvasive diagnostic methods, such as small bowel ultrasound, have high sensitivity and specificity for the detection of postoperative recurrence and are being evaluated as independent methods of assessment. Studies have also shown a reduction in endoscopic recurrence with postoperative anti-TNFα therapy. However, preoperative exposure to anti-TNFα therapy may impact postoperative response to these medications, and therefore, determining optimal postoperative prophylaxis strategy for biologic-experienced patients requires further exploration. Lastly, new surgical modalities to reduce postoperative recurrence are currently being investigated with preliminary data suggesting that an antimesenteric functional end-to-end anastomosis (Kono-S) may decrease postoperative recurrence.

Guidelines for the management of patients with Crohn's disease. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2012. It contains 46 recommendations for the diagnosis and treatment, both pharmacological and surgical, of Crohn's disease in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality and strength of the available recommendations. The degree of expert support for the proposed statement, assessment of the quality of evidence and the strength of the recommendation was assessed on a 6-point Likert scale. Voting results, quality and strength ratings with comments are included with each statement.

Thiopurines in Inflammatory Bowel Disease. How to Optimize Thiopurines in the Biologic Era?

Thiopurines have been a cornerstone in the treatment of inflammatory bowel disease (IBD). Although they have been used for more than 50 years, there are still some unsolved issues about their efficacy and, also, some safety concerns, mainly the risk of myelosuppression and life-threatening lymphoproliferative disorders. Furthermore, the development of biological therapy raises the question whether there is still a role for thiopurines in the IBD treatment algorithm. On the other hand, limited cost and wide availability make thiopurines a reasonable option in settings of limited resources and increasing prevalence of IBD. In fact, there is a growing interest in optimizing thiopurine therapy, since pharmacogenomic findings suggest that a personalized approach based on the genotyping of some molecules involved in its metabolism could be useful to prevent side effects. Polymorphisms of thiopurine methyltransferase enzyme (TPMT) that result in low enzymatic activity have been associated with an increased risk of myelotoxicity, especially in Caucasians; however, in Asians it is assumed that the variants of nudix hydrolase 15 (NUDT15) are more relevant in the development of toxicity. Age is also important, since in elderly patients the risk of complications seems to be increased. Moreover, the primo-infection of Epstein Barr virus and cytomegalovirus under thiopurine treatment has been associated with severe lymphoproliferative disorders. In addition to assessing individual characteristics that may influence thiopurines treatment outcomes, this review also discusses other strategies to optimize the therapy. Low-dose thiopurines combined with allopurinol can be used in hypermethylators and in thiopurine-related hepatotoxicity. The measurement of metabolites could be useful to assess compliance, identify patients at risk of adverse events and also facilitating the management of refractory patients. Thioguanine is also a rescue therapy in patients with toxicity related to conventional thiopurine therapy. Finally, the current indications for thiopurines in monotherapy or in combination with biologics, as well as the optimal duration of treatment, are also reviewed.

Use of thiopurines in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD), once considered a disease of the Western hemisphere, has emerged as a global disease. As the disease prevalence is on a steady rise, management of IBD has come under the spotlight. 5-Aminosalicylates, corticosteroids, immunosuppressive agents and biologics are the backbone of treatment of IBD. With the advent of biologics and small molecules, the need for surgery and hospitalization has decreased. However, economic viability and acceptability is an important determinant of local prescription patterns. Nearly one-third of the patients in West receive biologics as the first/initial therapy. The scenario is different in developing countries where biologics are used only in a small proportion of patients with IBD. Increased risk of reactivation of tuberculosis and high cost of the therapy are limitations to their use. Thiopurines hence become critical for optimal management of patients with IBD in these regions. However, approximately one-third of patients are intolerant or develop adverse effects with their use. This has led to suboptimal use of thiopurines in clinical practice. This review article discusses the clinical aspects of thiopurine use in patients with IBD with the aim of optimizing their use to full therapeutic potential.

Medical therapies for postoperative Crohn's disease

Postoperative recurrence of Crohn's disease is common and requires a multidisciplinary approach between surgeons and gastroenterologists in the perioperative and postoperative period to improve outcomes in this patient population. Endoscopic recurrence precedes clinical and surgical recurrence and endoscopic monitoring is crucial to guide postoperative management. Risk stratification of patients is recommended to guide early prophylactic management, and follow-up endoscopic monitoring can guide intensification of therapy. This review summarizes evidence behind postoperative recurrence rates, disease monitoring techniques, nonbiologic and biologic therapies available to prevent and treat postoperative recurrence, risk factors associated with recurrence, and postoperative management strategies guided by endoscopic monitoring.

Thiopurines: Recent Topics and Their Role in the Treatment of Inflammatory Bowel Diseases

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic inflammatory bowel diseases (IBD) of unknown etiology, characterized by repeated relapse and remission. The efficacy of thiopurine in IBD was first reported in the late 1960s. Thiopurines are used to alleviate the symptoms of IBD, especially UC. These drugs have a steroid-sparing potential and are widely used for the purpose of maintaining long-term remission in steroid-dependent cases. Therefore, thiopurines tend to be used long-term, but adverse events that accompany long-term use, such as lymphoproliferative disorders, must be monitored with care. In contrast, thiopurine plays a critical role in controlling the immunogenicity of biologics. Furthermore, although thiopurine is an old drug, new findings, including the prediction of serious adverse events such as severe alopecia and acute advanced leukopenia, by nudix hydrolase 15 gene polymorphism analysis, as well as the possibility of appropriate drug monitoring by detailed analysis of 6-thioguanine nucleotides have been clarified. However, the consequences of thiopurine withdrawal have not been determined and further studies, including randomized controlled trials, are necessary to answer the clinical question regarding the scenarios in which thiopurine withdrawal is possible.

Evidence-based clinical practice guidelines for inflammatory bowel disease 2020

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.

A rare case of pediatric Crohn's disease and alveolar bone loss: a report and review

Crohn's disease (CD) is a granulomatous inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract, but its etiology is still unclear. CD patients usually have extraintestinal manifestations including oral manifestations, and this can also occasionally appear in children. Oral manifestations, including aphthous stomatitis, typically develop on the mucocutaneous tissue. As pediatric CD is not common, there have been no reports concerning alveolar bone resorption for these kinds of patients. An 11-year-old Chinese girl was referred to our hospital because of reoccurring painful oral ulcers, with a 2.5-year history of CD and recurrent oral ulcers. Clinical examinations revealed intestinal lesions, oral ulcers, and alveolar bone loss. CD and its related periodontitis were diagnosed. After comprehensive therapy, including periodontal scaling and anti-inflammatory treatment, the oral ulcers gradually healed. One year later, follow-up visit showed the anterior alveolar bone to be stable and new alveolar bone regenerating around the mandibular anterior teeth at some sites. It is rare for CD children to have periodontitis, especially with severe alveolar bone loss. This case suggests that when treating periodontitis in children, the possibility of systemic disease, such as CD, should be considered and attended to. Early diagnosis and symptomatic treatment and care are crucial.

Colonoscopy-guided therapy for the prevention of post-operative recurrence of Crohn's disease

BACKGROUND

About half of patients with Crohn's disease (CD) require surgery within 10 years of diagnosis. Resection of the affected segment is highly effective, however the majority of patients experience clinical recurrence after surgery. Most of these patients have asymptomatic endoscopic recurrence weeks or months before starting with symptoms. This inflammation can be detected by colonoscopy and is a good predictor of poor prognosis.Therapy guided by colonoscopy could tailor the management and improve the prognosis of postoperative CD.

OBJECTIVES

To assess the effects of prophylactic therapy guided by colonoscopy in reducing the postoperative recurrence of CD in adults.

SEARCH METHODS

The following electronic databases were searched up to 17 December 2019: MEDLINE, Embase, CENTRAL, Clinical Trials.gov, WHO Trial Registry and Cochrane IBD specialized register. Reference lists of included articles, as well as conference proceedings were handsearched.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs and cohort studies comparing colonoscopy-guided management versus management non-guided by colonoscopy.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies for eligibility, extracted the data and assessed study quality. Methodological quality was assessed using both the Cochrane 'Risk of bias' tool for RCTs and Newcastle-Ottawa scale (NOS) for cohort studies. The primary outcome was clinical recurrence. Secondary outcomes included: endoscopic, surgical recurrence and adverse events. We calculated the risk ratio (RR) for each dichotomous outcome and extracted the hazard ratio (HR) for time-to-event outcomes. All estimates were reported with their corresponding 95% confidence interval (CI). Data were analysed on an intention-to-treat (ITT) basis. The overall quality of the evidence was evaluated using GRADE criteria.

MAIN RESULTS

Two RCTs (237 participants) and five cohort studies (794 participants) met the inclusion criteria. Meta-analysis was not conducted as the studies were highly heterogeneous. We included two comparisons. Intensification of prophylactic-therapy guided by colonoscopy versus intensification guided by clinical recurrence One unblinded RCT and four retrospective cohort studies addressed this comparison. All participants received the same prophylactic therapy immediately after surgery. In the colonoscopy-based management group the therapy was intensified in case of endoscopic recurrence; in the control group the therapy was intensified only in case of symptoms. In the RCT, clinical recurrence (defined as Crohn's Disease Activity Index (CDAI) > 150 points) in the colonoscopy-based management group was 37.7% (46/122) compared to 46.1% (21/52) in the control group at 18 months' follow up (RR 0.82, 95% CI: 0.56 to 1.18, 174 participants, low-certainty evidence). There may be a reduction in endoscopic recurrence at 18 months with colonoscopy-based management (RR 0.73, 95% CI 0.56 to 0.95, 1 RCT, 174 participants, low-certainty evidence). The certainty of the evidence for surgical recurrence was very low, due to only four cohort studies with inconsistent results reporting this outcome. Adverse events at 18 months were similar in both groups, with 82% in the intervention group (100/122) and 86.5% in the control group (45/52) (RR 0.95, 95% CI:0.83 to 1.08, 1 RCT, 174 participants, low-certainty of evidence).The most common adverse events reported were alopecia, wound infection, sensory symptoms, systemic lupus, vasculitis and severe injection site reaction. Perforations or haemorrhages secondary to colonoscopy were not reported. Initiation of prophylactic-therapy guided by colonoscopy versus initiation immediately after surgery An unblinded RCT and two retrospective cohort studies addressed this comparison. The control group received prophylactic therapy immediately after surgery, and in the colonoscopy-based management group the therapy was delayed up to detection of endoscopic recurrence. The effects on clinical and endoscopic recurrence are uncertain (clinical recurrence until week 102: RR 1.16, 95% CI 0.73 to 1.84; endoscopic recurrence at week 102: RR 1.16, 95% CI 0.73 to 1.84; 1 RCT, 63 participants, very low-certainty evidence). Results from one cohort study were similarly uncertain (median follow-up 32 months, 199 participants). The effects on surgical recurrence at a median follow-up of 50 to 55 months were also uncertain in one cohort study (RR 0.79, 95% CI 0.38 to 1.62, 133 participants, very low-certainty evidence). There were fewer adverse events with colonoscopy-based management (54.8% (17/31)) compared with the control group (93.8% (30/32)) but the evidence is very uncertain (RR 0.58, 95% CI 0.42 to 0.82; 1 RCT, 63 participants). Common adverse events were infections, gastrointestinal intolerance, leukopenia, pancreatitis and skin lesions. Perforations or haemorrhages secondary to colonoscopy were not reported.

AUTHORS' CONCLUSIONS

Intensification of prophylactic-therapy guided by colonoscopy may reduce clinical and endoscopic postoperative recurrence of CD compared to intensification guided by symptoms, and there may be little or no difference in adverse effects. We are uncertain whether initiation of therapy guided by colonoscopy impacts postoperative recurrence and adverse events when compared to initiation immediately after surgery, as the certainty of the evidence is very low. Further studies are necessary to improve the certainty of the evidence of this review.

Interventions for maintenance of surgically induced remission in Crohn's disease: a network meta-analysis

BACKGROUND

Crohn's disease (CD) is a chronic disease of the gut. About 75% of people with CD undergo surgery at least once in their lifetime to induce remission. However, as there is no known cure for the disease, patients usually experience a recurrence even after surgery. Different interventions are routinely used in maintaining postsurgical remission. There is currently no consensus on which treatment is the most effective.

OBJECTIVES

To assess the effects and harms of interventions for the maintenance of surgically induced remission in Crohn's disease and rank the treatments in order of effectiveness.

SEARCH METHODS

We searched the Cochrane IBD Group Specialized Register, CENTRAL, MEDLINE, and Embase from inception to 15 January 2019. We also searched reference lists of relevant articles, abstracts from major gastroenterology meetings, ClinicalTrials.gov, and the WHO ICTRP. There was no restriction on language, date, or publication status.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) that compared different interventions used for maintaining surgically induced remission in people with CD who were in postsurgical remission. Participants had to have received maintenance treatment for at least three months. We excluded studies assessing enteral diet, diet manipulation, herbal medicine, and nutritional supplementation.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected relevant studies, extracted data, and assessed the risk of bias. Any disagreements were resolved by discussion or by arbitration of a third review author when necessary. We conducted a network meta-analysis (NMA) using a Bayesian approach through Markov Chain Monte Carlo (MCMC) simulation. For the pairwise comparisons carried out in Review Manager 5, we calculated risk ratios (RR) with their corresponding 95% confidence intervals (95% CI). For the NMA, we presented hazard ratios (HR) with corresponding 95% credible intervals (95% CrI) and reported ranking probabilities for each intervention. For the NMA, we focused on three main outcomes: clinical relapse, endoscopic relapse, and withdrawals due to adverse events. Data were insufficient to assess time to relapse and histologic relapse. Adverse events and serious adverse events were not sufficiently or objectively reported to permit an NMA. We used CINeMA (Confidence in Network Meta-Analysis) methods to evaluate our confidence in the findings within networks, and GRADE for entire networks.

MAIN RESULTS

We included 35 RCTs (3249 participants) in the review. The average age of study participants ranged between 33.6 and 38.8 years. Risk of bias was high in 18 studies, low in four studies, and unclear in 13 studies. Of the 35 included RCTs, 26 studies (2581 participants; 9 interventions) were considered eligible for inclusion in the NMA. The interventions studied included 5-aminosalicylic acid (5-ASA), adalimumab, antibiotics, budesonide, infliximab, probiotics, purine analogues, sulfasalazine, and a combination of sulfasalazine and prednisolone. This resulted in 30 direct contrasts, which informed 102 mixed-treatment contrasts.The evidence for the clinical relapse network (21 studies; 2245 participants) and endoscopic relapse (12 studies; 1128 participants) were of low certainty while the evidence for withdrawal due to adverse events (15 studies; 1498 participants) was of very low certainty. This assessment was due to high risk of bias in most of the studies, inconsistency, and imprecision across networks. We mainly judged individual contrasts as of low or very low certainty, except 5-ASA versus placebo, the evidence for which was judged as of moderate certainty.We ranked the treatments based on effectiveness and the certainty of the evidence. For clinical relapse, the five most highly ranked treatments were adalimumab, infliximab, budesonide, 5-ASA, and purine analogues. We found some evidence that adalimumab (HR 0.11, 95% Crl 0.02 to 0.33; low-certainty evidence) and 5-ASA may reduce the probability of clinical relapse compared to placebo (HR 0.69, 95% Crl 0.53 to 0.87; moderate-certainty evidence). However, budesonide may not be effective in preventing clinical relapse (HR 0.66, 95% CrI 0.27 to 1.34; low-certainty evidence). We are less confident about the effectiveness of infliximab (HR 0.36, 95% CrI 0.02 to 1.74; very low-certainty evidence) and purine analogues (HR 0.75, 95% CrI 0.55 to 1.00; low-certainty evidence). It was unclear whether the other interventions reduced the probability of a clinical relapse, as the certainty of the evidence was very low.Due to high risk of bias and limited data across the network, we are uncertain about the effectiveness of interventions for preventing endoscopic relapse. Whilst there might be some evidence of prevention of endoscopic relapse with adalimumab (HR 0.10, 95% CrI 0.01 to 0.32; low-certainty evidence), no other intervention studied appeared to be effective.Due to high risk of bias and limited data across the network, we are uncertain about the effectiveness of interventions for preventing withdrawal due to adverse events. Withdrawal due to adverse events appeared to be least likely with sulfasalazine (HR 1.96, 95% Crl 0.00 to 8.90; very low-certainty evidence) and most likely with antibiotics (HR 53.92, 95% Crl 0.43 to 259.80; very low-certainty evidence). When considering the network as a whole, two adverse events leading to study withdrawal (i.e. pancreatitis and leukopenia) occurred in more than 1% of participants treated with an intervention. Pancreatitis occurred in 2.8% (11/399) of purine analogue participants compared to 0.17% (2/1210) of all other groups studied. Leukopenia occurred in 2.5% (10/399) of purine analogue participants compared to 0.08% (1/1210) of all other groups studied.

AUTHORS' CONCLUSIONS

Due to low-certainty evidence in the networks, we are unable to draw conclusions on which treatment is most effective for preventing clinical relapse and endoscopic relapse. Evidence on the safety of the interventions was inconclusive, however cases of pancreatitis and leukopenia from purine analogues were evident in the studies. Larger trials are needed to further understand the effect of the interventions on endoscopic relapse.